I am having problems referencing controls and their properities the various templates in form_view. I need to set the visible property to false on a button in the item_template. I looked in the HELP section and there was a reference hyperlink called "Web Forms Control Identification" but the link is invalid. I have tried to do the following in the page_load subroutine.

dim var_deletebutton as new button
var_deletebutton = CType(me.formview1.findcontrol("bt_Delete"), button)
var_deletebutton.visible = false

I get this error when the program executes the second line of code:
"There is no source code available for the current location".

Can anyone help me?

thanks

dave potter:)

How does your markup for the Form View look like? And what template are you trying to access? Is the FormView's FormViewMode valid for the template you're accessing? That is, are you sure that, say, your FormView is in Edit mode and you're trying to access controls in the Edit template?

The code you posted works for me in a number of pages. BTW, there is no need to instantiate an instance of the Button. The FindControl method will do that for you:HtH,

Imar

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Imar Spaanjaars
Everyone is unique, except for me.

Thanks Imar for your response. Here are the answers to your questions.


(1) What Template are you trying to access? - Item_template

(2)Is the formView's formviewmode valid for the template you're accessing? - The form opens up in the select mode not edit mode. On this screen I want to show or hide the "DELETE" button.

(3) I took out "NEW" and still had the same error.


(4) Here is some of the code in the ITEMTEMPLATE
<ItemTemplate>
  <asp:Button ID="bt_Delete" runat="server" CausesValidation="False" CommandName="delete"Font-Bold="True" Font-Names="Arial" Font-Size="8pt" Style="z-index: 102; left: 672px; position: absolute; top: 56px" Text="Delete Record" Width="88px" />
  <asp:Button ID="bt_edit" runat="server" CausesValidation="False" CommandName="edit" Font-Bold="True" Font-Names="Arial" Font-Size="8pt" Style="z-index: 102; left: 656px;
                    position: absolute; top: -78px" Text="Edit" UseSubmitBehavior="False"
                    Width="120px" />

In my page_load subroutine, I check to see if the user has permission to delete a record, if they don't I want to make the button invisible.
thanks for your help.

dave

I got it to work ... when I just ran it. It failed only when I put a break point on it and tried running it by hitting F11 until I came to the line.

THANKS FOR ALL YOUR HELP :)

Glad it's working, although it's strange that it fails when debugging....


Imar
---------------------------------------
Imar Spaanjaars
Everyone is unique, except for me.

Hi Imar

I am having a similar problem in VS2005 I am trying to access 2 DropDownLists in a FormView control in edit mode. Everything that I try wont let me access the control. I have tried using the FindControl Method but it never seems to return the control and I get Object Reference Not Set to an Instance of Object. Here is the code.


Dim var_ddl1 As New DropDownList
Dim var_ddl2 As New DropDownList
Dim var_txt1 As New TextBox
Dim var_txt2 As New TextBox
var_ddl1 = CType(Me.FormView1.FindControl("DropDownList1"), DropDownList)
var_ddl2 = CType(Me.FormView1.FindControl("DropDownList2"), DropDownList)
var_txt1 = CType(Me.FormView1.FindControl("txtAppID"), TextBox)
var_txt2 = CType(Me.FormView1.FindControl("txtPIID"), TextBox)
var_ddl1.SelectedValue = var_txt1.Text
var_ddl2.SelectedValue = var_txt2.Text

What I want to eventually do is access the DropDownList1 SelectIndexChange method and re-bind the DropDownList2 control.

Is what I want to do even possible?

Hi Imar

I am having a similar problem in VS2005 I am trying to access 2 DropDownLists in a FormView control in edit mode. Everything that I try wont let me access the control. I have tried using the FindControl Method but it never seems to return the control and I get Object Reference Not Set to an Instance of Object. Here is the code.


Dim var_ddl1 As New DropDownList
Dim var_ddl2 As New DropDownList
Dim var_txt1 As New TextBox
Dim var_txt2 As New TextBox
var_ddl1 = CType(Me.FormView1.FindControl("DropDownList1"), DropDownList)
var_ddl2 = CType(Me.FormView1.FindControl("DropDownList2"), DropDownList)
var_txt1 = CType(Me.FormView1.FindControl("txtAppID"), TextBox)
var_txt2 = CType(Me.FormView1.FindControl("txtPIID"), TextBox)
var_ddl1.SelectedValue = var_txt1.Text
var_ddl2.SelectedValue = var_txt2.Text

What I want to eventually do is access the DropDownList1 SelectIndexChange method and re-bind the DropDownList2 control.

Is what I want to do even possible?

Hi there,

You don't just "access the SelectedIndexChanged" event; that event is fired by the run-time for you, so you can write code for it.

Anyway, no need for all this wizardry; all you need is an event defined on the drop-down:

<asp:FormView ID="FormView1" runat="server" DefaultMode="Insert">
  <InsertItemTemplate>
    <asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="true" OnSelectedIndexChanged="MyMethod">
      <asp:ListItem>1</asp:ListItem>
      <asp:ListItem>2</asp:ListItem>
      <asp:ListItem>3</asp:ListItem>
      <asp:ListItem>4</asp:ListItem>
    </asp:DropDownList>
  </InsertItemTemplate>
</asp:FormView>

and then in your code behind:

Protected Sub MyMethod(ByVal sender As Object, ByVal e As System.EventArgs)
    Dim selectedValue As String = _
      CType(FormView1.FindControl("DropDownList1"), DropDownList).SelectedValue
End Sub

FindControl will search in the current "NamingContainer" which makes it possible to return the drop down list, even though it's actually inside an EditItemTemplate or possible even inside, say an Html table.

I think that should do the trick.

One other thing: this code is not very efficient:

Dim var_ddl1 As New DropDownList
var_ddl1 = CType(Me.FormView1.FindControl("DropDownList1"), DropDownList)


First, you declare a variable named var_ddl1 (which, IMO, is a very confusing name; all variables are variables, so there is no need to prefix them with var; do yourself a favor (and all your (future) colleagues as well) and use something like lstEmployeeNumber, or lstState or even State or ddlState; these names are much easier to read *and* understand) and then you assign it a *new* instance of a DropDownList, which will be created in memory for you.
The next line then assigns the return value of the FindControl method to var_ddl1 (did I already mention that's a confusing name?) effectively overwriting the first one. SO, the first one is actually never used and is just a waste of Cpu cycles and memory.

This is a lot better:

Dim var_ddl1 As DropDownList
var_ddl1 = CType(Me.FormView1.FindControl("DropDownList1"), DropDownList)

or even:

Dim var_ddl1 As DropDownList = CType(Me.FormView1.FindControl("DropDownList1"), DropDownList)

or yet even better:

Dim lstState As DropDownList = CType(Me.FormView1.FindControl("lstState"), DropDownList) .... ;)


HtH,

Imar
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Imar Spaanjaars
Everyone is unique, except for me.
While typing this post, I was listening to: Freaky Styley by Red Hot Chili Peppers (Track 6 from the album: Freaky Styley) What's This?

Hi, Imar.

How would I write the same code in ASP .NET C# in order to set the visible property value to false on a button in the item_template. Thanks.

C# doesn't use CType, but you can put the name of the control type in parentheses before an object to cast it. Something like this would work:

Button myButton = (Button) FormView1.FindControl("Button1");
myButton.Visible = false;

For more help with code converting issues, you may want to take a look at the code converter at Dot Net Taxi: http://www.dotnettaxi.com/Tools/Converter.aspx

HtH,

Imar
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Imar Spaanjaars
Everyone is unique, except for me.
Author of ASP.NET 2.0 Instant Results and Beginning Dreamweaver MX / MX 2004